Flexible door closure



1969 w. R. YOUNGS 3,421,568

.FLEXIBLE DOOR CLOSURE Filed June 29, 1966 I4 INi ENTOR 74 \kmbur R-\Qmmss h77777777777777 MA/W- ATTORNEY United States Patent 3,421,568FLEXIBLE DOOR CLOSURE Wilbur R. Youngs, 1905 Queenswood Drive, Findlay,Ohio 45840 Filed June 29, 1966, Ser. No. 561,627 US. Cl. 160310 Int. Cl.E06b 3/00 10 Claims ABSTRACT OF THE DISCLOSURE Although this inventionhas applicability to many uses including, for example, gymnasium ormeeting room dividers, it will be described in reference to a closurefor an airplane hangar. The structures commonly employed as closures forthe openings of airplane hangars are necessarily large, and because ofthe necessity for ability to withstand heavy wind loading, are also ofquite substantial and heavy construction. These closures are normally ofthe laterally sliding or folding type, or they move as a single unitfrom a vertical position to an elevated position which approaches thehorizontal. A principal problem with closures of such conventional typesfor airplane hangars is in the heat loss during cold weather each timethe doors must be opened. This heat loss is substantially the sameregardless of the size of the airplane, because for each opening, theclosure is removed substantially completely, and to its maximum height,i.e., the height of the header above the ground. Heat which accumulatesin the upper portion of the hanger is then allowed to escape. On alarger hangar having, for example, a 90-foot opening, this loss isconsiderable.

Flexible curtains or closures for hangar door openings have beenpreviously disclosed, and reference may be had to my Patent 3,211,211dated Oct. 12, 1965. This latter structure overcomes the problem of heatloss for the reason that the flexible curtain is removed from andreturned to closing position by means of a traveling roller supportedentirely by the flexible panel or curtain. By applying force to the endof the roll to cause it to roll upwardly or downwardly, it will rollitself into the curtain or unroll itself from the curtain, as the casemay be. Thus, where a small aircraft is being removed from the hangar,for example, the curtain need by raised only halfway thereby saving asubstantial portion of the heat which would otherwise be lost.

The present invention embodies an entirely different principle from theinvention of my prior patent. Instead of a movable roller, I employ afixed roller secured across the top of the opening which is to be closedand mounted there for rotation. In order that the flexible curtain maybe a continuous sheet across the entire opening, it is possible only tosupport the roller, onto which the flexible curtain is wrapped or woundduring opening, at the extremities of the roller. To span a greatdistance with a roller without encountering sagging would require anunduly expensive structure. Accordingly, in carrying out the presentinvention, one or more support members is or are disposed intermediatethe extremities of the roller, and secured adjacent the roller to theadjacent structure, for example, the lintle, or header member. Thesupporting means are conveniently embodied in the form. of one "ice ormore rollers preferably defining a cradle for supporting the maincurtain roller and accommodating a variable amount of curtain materialwhich is wound about the main curtain roller.

Such a structure contemplates that the curtain material shall invirtually all positions of the curtain relative to the ground level beinterposed between the main curtain roller and the support roll orrollers.

It has been found that the plastic materials from which the flexiblemembranes or curtains are made, when submitted to the forces arisingwhen portions thereof are interposed between the main curtain roller andthe sup port means, undergo a moderate amount of elongation orstretching. If this elongation or stretching of the curtain material inthe region of the support means is not compensated for, the curtain willundergo folding and wrinkling in the region of the support meansresulting in excessive build-up of material on the roller, excessivewear, and unsightly appearance. To overcome this, it has been found thatthe diameter of the main flexible curtain roller should be increased apredetermined amount in the region where it will be in indirect contactwith the intermediate supporting means through the flexible curtainmaterial. This invention, then, makes possible the provision of a widespan, flexible curtain operated from a fixed overhead roller ofrelatively small diameter and simple construction, and avoids theproblems attendant a long span roller supported by the curtain andmoving towards and away from the header member. Not only does it takeconsiderable power to elevate such a roller, but the structureencounters problems when dirt, tools, foreign matter, ice, etc. arecaught in the bight between the moving roller and the curtain. Thestructures of the present invention are much simpler, more economical tooperate, avoid all of the difficulties attendant a moving rollerstructure, and are made possible by the invention hereof.

This invention may be better understood by having reference to theannexed drawings wherein:

FIG. 1 is a fragmentary perspective view of the front portion of anairplane hanger showing the exterior appearance of a flexible closure inaccordance with the present invention in a partially open position;

FIG. 2 is a rear view on a somewhat larger scale of the closurestructure and showing the fixed main roller rotatably supported on thelintle of the opening, the support means, the flexible curtain, andmeans for driving the roller to raise and lower the curtain;

FIG. 3 is a fragmentary cross-sectional view taken in the planeindicated by the line 3-3 in FIG. 2, and showing the details of apreferred form of support means for the roller to prevent sagging;

FIG. 4 is a plan view of a roller adapted for use with a flexiblecurtain and supported at two intermediate points, and showing theenlarged diameter of the roll to accommodate stretched material at thesepoints;

FIG. 5 is a section showing the details of a roller support carriagewith a pair of support rolls defining a cradle;

FIG. 6 is a detail view of a curtain locking device useful with theclosures hereof.

Referring more particularly to FIG. 1, there is here shown indiagrammatic form a fragmentary perspective view of an airplane hangar10 having an opening 12 partially closed by flexible curtain 14.Flexible curtain 14 is dimensioned to cover the opening 12 when in itsfully extended position, and is provided along its lower marginal edgewith a bead 16 suitably secured thereto and adapted to coact with theground level or sill 18 to effect a closure therewith. Means coactingbetween the beads 16 and the sill 18 may be provided to lock the door inthe closed position, as will be hereinafter more particularlyexemplified and described.

Referring more particularly to FIG. 2, there is here shown the closureof FIG. 1 from the reverse side in somewhat more detail and on anenlarged scale. Curtain 14 is shown in a partly open position with head16 secured along the lower marginal edge. It will be understood that anysuitable means for securing the bead 16 or an equivalent structure alongthe lower marginal edge may be employed. Bead 16 is desirably ofsubstantial weight in order to exert a tensioning effect on the curtain.

Curtain 14 is conveniently formed of a very tough, thin-section plasticmaterial, for example, a nylon fiber reenforced vinyl sheet, a neoprenesheet, polyester fiber reenforced nylon sheet, or the like. Usually, thelarge section panels of sufficient dimension to cover the opening of anairplane hangar are formed from a plurality of strips of the toughplastic sheeting material which are heat sealed along overlappedmarginal edges to provide a continuous sheet of the proper dimension.The heat seals of panel 14 are shown in FIG. 2 and indicated by thenumeral 20. Such heat seals should be vertically disposed relative tothe opening covered by the flexible closure. For most purposes, a heatseal in width to about 1 in width is most satisfactory, best resultsbeing secured with the wider heat seal.

Along the marginal edges of the opening 12 there are provided a pair ofparallel vertically disposed guides suitably secured to the verticalmargins defining the opening 12 and forming a channel or way 24 in whichthe lateral marginal edges 26 of the curtain 14 are free to move. Roller28 spans the entire length of.the opening 12 and is mounted andjournaled for rotation in bearings 30 at each end of the roller, whichbearings 30 are in turn secured to the lintle 32 across the top ofopening 12. Roller 28 is better shown in cross-section in FIG. 3, itbeing obscured from view by convolutions of the flexible curtain 14 inFIG. 2. Roller 28 is, however, conveniently a steel tube, preferablyabout 4.5" in diameter and dimensioned to span the opening. As indicatedabove, these openings may vary, depending upon the ultimate use of theclosure from to as much as 100 feet or more. To accommodate the largestairliners in current use, openings of as much as 200 feet may berequired. Depending upon the overall span, the basic tube diameter mayrange from about 2.5" to about 12" for most purposes. The diameter ofthe basic roller is not critical.

As shown in FIG. 2, support means are provided intermediate theextremities of the roller to prevent the roller 28 from sagging. If theroller 28 were allowed to sag, it would be impossible to raise and lowerthe curtain without encountering extreme wrinkling, distortion, andpossible destruction of the flexible membrane. In the embodiment shownin FIG. 2, two such support means are provided, although it will beunderstood that one or more roller sup-port means may be provided. It isa relatively simple matter to calculate how many such supports arerequired for a roller of given physical properties, diameter, and lengthin order to eliminate sag. Usually, for a six inch steel tube havingwalls about 0.3 thick, about 8 to 10 feet can be tolerated withoutintermediate support. Of course, the more flexible the tube, the shorterthe span that can be tolerated without support.

Accordingly, in FIG. 2, there are provided supports 34, desirably aboutuniformly spaced from the extremities of the roller 28 and from eachother, and secured by any suitable means such as bolts 56 to the headeror lintle 32. As best shown in FIG. 3, the supports 34 include a bracket38 which is contoured to extend from the lintle 32 rearwardly anddownwardly to support in turn a carriage 40 for disposition below and insupporting relation with respect to the roller 28. Carriage 46 isprovided in the embodiment shown in the annexed drawings with a pair ofparallel rollers 42 journaled for rotation in the carriage 40 with theiraxes parallel to the axis of roller 28. The bracket 38 of support 34 maydesirably be somewhat flexible to accommodate relative movement betweenthe main curtain roller 28 and the support rolls 42"due to build-up ofthe flexible curtain material 14 in convolutions about the roller 28.Alternatively and conveniently, the rollers 42 are provided with aresilient rubber coating able to accommodate the relatively slightbuild-up in the relatively few revolutions required to fully raise thecurtain. The carriage 40 is of very simple structure and is composed ofa pair of parallel side rails 44 and 46, each having a pair of spacednotches 48 adapted to receive axial pins 50 in the rollers 42. The siderails 44 and 46 of carriage 40 are conveniently welded to the supportbracket 38 at its lower extremity as shown in FIG. 3. The forwardportion of the carriage 40 adjacent to curtain 14 may be open or closedby a suitable header or crossmember if desired. As shown in FIGS. 2 and3, no such cross-member is provided.

The rollers 42 may be of conventional design of the type used in rollertype conveyors, such conveyors being commonly used for conveying boxesof material from one point to another in a packaging plant, andpreferably provided with a skin of resilient rubber.

FIG. 4 shows in greater detail a main roller 28. The terminal portionsof the roller are provided with shaft ex tensions 52 and 54 adapted tobe journaled for rotation in bearings 30 (FIG. 2). Shaft extension 54 isalso provided with a splined end portion 56 to accept a gear 60- formeshing coaction with drive gear 62 operating from a motor-gearreduction apparatus of conventional design generally indicated at 64 inFIG. 2. While electric drive means have been shown in the preferredembodiment illustrated in FIG. 2, it will be understood that anysuitable driving means, manual, pneumatic, hydraulic, electric, or anycombination of these may be employed to rotate roller 28 about its ownaxis in a relatively fixed position to raise and lower curtain 14.

The curtain roller 28 is provided with diametral enlargements 66, thecenters being located at approximately the 25% of the length of the rod28 and the 75% marks of the rod 28 calculated from the left-hand end,respectively, and are designed to be located for coaction with thesupports 34. The amount of increase in the diameter will depend to someextent upon the plastic which is used. In the preferred case, thecurtain is formed of a nylon thread reenforced vinyl sheeting materialwhich has a thickness of about 0.025", and is characterized by aremarkable property of memory. Once the material is stretched out ofshape in any region, it gradually reassumes the original dimension andcontour which it possessed prior to the stressing. This is a verydesirable attribute from the standpoint of appearance of the door. Withsuch a curtain of. 0.025" thickness, it has been determined that abuild-up 66 is formed by wrapping around the roller 28 approximately 3.0times a strip of the same curtain material having a width preferablyslightly greater than the width of the roller 42. More specifically fora 4.5" diameter roller 28, the length of the strip wrapped about theexterior of the roller 28 is 43" of the same curtain material. This willprovide a build-up of sufficient increase in diameter to compensate forthe stretch which will occur in the curtain at the supporting rollers 0rsupport means when operating the curtain from the fully closed positionto the fully open position. For best results, the built-up portion 66 isfared out smoothly to the diameter of the adjacent sections with thecement material. With the other heat sealable plastic materials, theextent of stretching may not be precisely the same as with the aforesaidnylon-vinyl material which is preferred for use in airplane hanger doorapplications and gymnasium applications. However, it is a simple matterto calculate the amount of build-up which will be required toaccommodate the stretch imposed by the rollers 42 on which the mainroller 28 rests and rotates. The nylon-vinyl plastic is preferredbecause of its excellent weatherability and extreme toughness. It can beobtained in a variety of colors and in white from commercial sources.

The closures of the present invention are also desirably provided withlocking means which may be of very simple structure. As shown in FIG. 6,a locking pin 70 of very simple design may be extended through an angleplate 72 secured through a sill plate 73 to the sill 18, through anaperture 74 in the bead 16 and through a second angle plate 75, alsosecured to sill plate 73. When the pins 70 are inserted through theangle plates 72 and 75 and through the cooperating aperture 74 in thebeam 16, the door is locked in the down position, and the application ofa slight amount of tension by attempting to raise the door while thepins are restraining it against upward movement applies a tension to thecurtain 14 which increases the wind resistance of the curtain 14 andalso serves to obliterate quickly any wrinkles which may have formed inthe curtain.

There has thus been provided a flexible closure for an opening which isparticularly adapted for use as a closure for an opening in an airplanehangar, but is equally adaptable for use as a garage door, a roomdivider, a gymnasium divider, or any other opening where a substantialspan for the fixed roller for the flexible curtain is encountered. Undersuch circumstances, unless supporting means are provided for the roller,the roller will sag. In most cases, where a steel roller is contemplatedhaving a diameter of about 2.5" up to about 12", a span in excess ofabout feet is contemplated. For smaller diameter rollers, shorter spans,of course, are contemplated. In any event, when such supports areprovided and result in rolling action against the surface of theflexible membrane dimensioned to cover the opening, there results astretching of the material in the area where the support means bearsagainst the curtain. In the absence of a roller including an enlargeddiameter in the region of such support means, the wear is so excessiveand the build-up of such a nature that the device is soon renderedinoperable, unsightly, or the curtain itself is destroyed. Thisinvention overcomes these difliculties and makes possible thefabrication of flexible membrane closures which span very largedistances and which but for the present invention have not heretoforebeen possible in this simplified form. Moreover, because of theenlargement of the roll diameter at the point of support, the effect itis distribute the load more evenly to all portions of the curtain.

What I claim is:

1. A flexible closure for an opening defined by a head member, a pair ofspaced parallel side members or jambs, and a base or sill comprising incombination:

(a) a flexible curtain dimensioned to cover the opening and having topand bottom marginal edges;

(b) a fixed roller spanning said opening and to which roller the topmarginal edge of said curtain is secured, said roller being mounted forrotation on an axis adjacent said head member whereby said curtain iswrapped on or unwrapped from said roller to raise and lower saidcurtain, respectively;

(c) means for supporting the roller and curtain to limit sagging of saidroller intermediate the extremities of the roller, convolutions of saidcurtain being disposed between said support means and said roller;

(d) diameter increasing means coacting between said roller intermediateits extremities and said support means in the region of said supportmeans, and dimensioned to compensate for any stretching of said curtainbetween said support means and said roller; and

(e) driving means mechanically coupled to and coacting directly withsaid roller at, at least, one extremity for directly applying arotational force thereto to Wrap said curtain on or unwrap said curtainfrom said roller.

2. A flexible closure in accordance with claim 1 which is furthercharacterized by the provision of a bead along the bottom marginal edgeof said flexible curtain.

3. A flexible closure in accordance with claim 2 wherein the beadincludes a pair of rigid angle members secured together and gripping thelower marginal edge of said flexible curtain on opposite sides thereof.

4. A flexible closure in accordance with claim 1 wherein the means forsupporting the roller and curtain includes a roller positioned forrolling and supporting contact with the surface of the curtain wrappedaround said fixed roller.

5. A flexible closure in accordance with claim 4 wherein said at leastone supporting roller is provided with a resilient rubber surface forcontact with said flexible curtain on said fixed roller.

6. A flexible closure in accordance with claim 1 wherein said supportmeans includes a bracket secured to the head member at one extremity,and having a carriage secured to its lower extremity, said carriageincluding a pair of spaced support rollers disposed with their axesparallel to the axis of said fixed roller and defining a cradle forsupporting said fixed roller at a point intermediate its extremities.

7. A flexible closure in accordance with claim 1 wherein the diameterincreasing means on said fixed roller comprises a wrapping of flexiblematerial about said roller and secured thereto.

8. A flexible closure in accordance with claim 7 wherein the flexiblematerial is of the same composition as the flexible curtain.

9. A flexible closure in accordance with claim 1 in which the flexiblecurtain is a fiber reenforced plastic sheet.

10. A flexible closure in accordance with claim 9 in which the fiberreenforced elements in said flexible curtain are nylon fibers.

References Cited UNITED STATES PATENTS 705,214 7/ 1902 Daus 242-735869,447 10/ 1907 McCloud -267 1,164,385 12/1915 Neupauer 160-264 X1,243,923 10/1917 Dargo 160-273 1,377,784 5/1921 Nodland 242-7351,655,260 1/1928 Dixson 160-264 1,776,119 9/1930 Johnson 160-23 X2,894,578 7/1959 Caesar et al. 160-308 3,292,685 12/1966 Clark 160-26FOREIGN PATENTS 584,631 10/ 1959 Canada.

PETER M. CAUN, Primary Examiner.

US. Cl. X.R. 160-267

